This invention relates to irrigation systems and particularly to a lawn area irrigation system that distributes and emits water below the surface at root level. The invention also encompasses a conduit apparatus for use in the system and a method of irrigating a lawn area by emitting water at root level.
Permanently installed lawn and landscape irrigation systems have become very popular in recent years. Common lawn and landscape irrigation systems include a network of underground PVC tubing which supplies irrigating water to sprinkler heads spaced out throughout the area of lawn to be watered. Although these permanent sprinkler head irrigation systems are much more convenient than manually positioning sprinkler heads, there are a number of problems associated with permanent sprinkler head type irrigation systems.
The most important problem with sprinkler head irrigation systems is that such systems make very inefficient use of irrigation water. Sprinkler head systems deliver water to an area too fast for the surface to absorb and thereby waste irrigation water through runoff. Also, complete coverage of an area requires that the sprinkler heads be spaced such that their coverage areas overlap, as much as sixty percent overlap is common. This coverage overlap exacerbates the runoff problem. Also, the spray created by the sprinkler heads increases evaporation loss and in windy conditions is often blown outside of the area to be watered and into streets and parking areas, for example.
Other problems with sprinkler head irrigation systems include the susceptibility of sprinkler heads to damage. Not only are the sprinkler heads susceptible to damage during mowing or during activities in the lawn area, the heads also pose hazards to persons using the lawn area. Also, spray from the sprinkler heads often discolors fences and adjacent structures. Furthermore, the deep trenching required for the network of PVC tubing makes installation costs fairly high.
Newer drip irrigation systems utilize subsurface water emitters to release irrigating water and avoid many of the problems associated with sprinkler head systems. However, drip irrigation systems are useful only for trees and shrubbery and are inefficient for use in irrigating lawns. The inefficiency arises because drip emitters deliver a major portion of the water to an area too deep to be useful to lawn grasses.